Manufacturing tolerances

The production of printed circuit boards is carried out according to the valid IPC guidelines and standards (et al. IPC-A-600 class 2) and on the basis of following technical specifications. HDI or MFT boards can be produced with smaller tolerances. Differing requirements of the customer must be explicitly agreed!

Pattern tolerances

The hole pattern for vias (DK) goes through all the layers of the circuit and therefore serves as a location reference for the other patterns.

Type

Tolerance

Type

Drilling pattern (PTH) to conductive pattern outer layers

Tolerance

±0,10mm

Type

Drilling pattern (PTH) to conductive pattern inner layers

Tolerance

±0,15mm

Type

Drilling pattern (PTH) to milling pattern / contour

Tolerance

±0,10mm

Type

Drilling pattern (NPTH) to milling pattern / contour

Tolerance

±0,10mm

Type

Drilling pattern (PTH) to marking print

Tolerance

±0,15mm

Type

Tolerance

Type

Conductive pattern to solder resist

Tolerance

±0,10mm

Type

Conductive pattern to marking print

Tolerance

±0,20mm

Type

Tolerance

Type

Hole to hole, one pass* (PTH-PTH or NPTH-NPTH)

Tolerance

±0,05mm

Type

Hole to hole, two passes (PTH-NPTH)

Tolerance

±0,10mm

* Also applies for PTH-NPTH if they are drilled in one run (e.g. location holes for SMD stencils).

Base material - rigid PCBs

Type

Tolerance

Type

Base material thickness

Tolerance

±10%

The information about the base material thickness exclusively defines the thickness of the dielectric including base copper. The other layer structures such as electroplated Cu layers or solder resist layers result in increased final thickness.

Specifications according to IPC-4204A. The information on the thickness of the base material defines solely the dielectric thickness or adhesive thickness incl. base copper. The other layer structures such as e.g. galvanic Cu or solder-stop lead to an increased circuit final thickness.

Rigid PCB thickness

Type

Tolerance

Type

Producibility level B (standard)

Tolerance

The higher value of ±10% or ±178µm

Thickness tolerances for pressed multilayers according to IPC-2222A. When measured over metallizations or coatings, those thicknesses and tolerances must be considered.

Flexible PCB thickness

Type

Tolerance

Type

Flexible part thickness

Tolerance

±50µm

Type

Flexible part + stiffener thickness

Tolerance

±100µm

Bow & Twist

For PCBs ≥ 0,8mm thickness

Tolerance

For PCBs ≥ 0,8mm thickness

with SMD

Tolerance

0,75%

For PCBs ≥ 0,8mm thickness

without SMD

Tolerance

1,50%

Please note that the twist & bow value is increased above average, if the copper balance of the PCB is locally very unequal or if the circuit board is very thin.